The present invention is directed to interactive television systems. In particular, the present invention is directed to interactive television systems which may be used to facilitate two-way communication between an end user and a provider center or service and which can be used to broadcast data files which may be accessed by a locally stored program to be displayed on a monitor as one or more presentations. The prior art has disclosed systems and devices which facilitate interactive television presentations.
Such prior art systems are characterized by the inclusion of dedicated phone or transmission lines or expensive hardware. The use of such dedicated systems drastically increases the cost associated with the use of such systems.
The PRODIGY.RTM. information service, which is marketed widely by Sears.RTM. and IBM.RTM. claims to use a distributed database architecture. However, that system only distributes the database to regional main frame computers. The underlying technology still relies on the maintenance of continuous real time two-way communication by a personal computer. Nearly all videotex services use phone lines and modems to link the two, although some experiments with two-way cable television and other media have been attempted. Such systems have exhibited numerous limitations.
Because each user of a traditional videotex system is directly connected to a central main frame computer when "on-line", the central computer must be capable of simultaneously handling the many subscribers it gets during prime usage periods. The central computer may sit idle the rest of the time. If there is a problem with a central computer or communications net linking it to the end users, the entire system may cease functioning. Thus, prior art systems have typically relied upon a computer/print interfaces.
The speed with which information may be retrieved in such systems is limited to the speed with which the central computer can recognize a user's request and locate the information in a central data storage media. Even the largest and fastest of central computers cannot overcome the limitations of how quickly information may be carried by the phone lines or other media that connect it to the user. Phone lines typically have a narrow bandwidth and can carry only a limited amount of information. Typical phone line communications are limited to a speed of 2400 baud.
The newer Integrated Services Digital Network (ISDN) and fiber optic cable technologies provide greater information transmission capability. However, even with high speed fiber optics which connect the central computer to a home terminal, the largest computers cannot keep up with an entire city, particularly during prime hours. These systems rely upon the single interaction of a computer and computer.
The bandwidth issue has never been adequately addressed because until recently all computer interfaces were just character-based or used very low resolution alpha mosaic-style displays utilizing protocol such as NAPLPS or TELETEL. Because these systems do not use attractive graphical interfaces, they are not pleasing to the eye. Graphical user interfaces have become very popular because they are far more interesting and easier to use. Such systems utilize much more memory storage space.
There are a number of prior art patents directed to interactive communications systems. U.S. Pat. Nos. 5,093,718 and 5,220,420 are directed to Interactive Home Information Systems. These patents disclose systems which incorporate a nodal structure which feeds in a broadband signal. The nodes are dedicated computers which reside outside of a house or group of houses. The nodes couple to head end computer which is preferably an industrial microprocessor-based controller with high capacity magnetic or optic read/write storage devices.
U.S. Pat. No. 5,233,436 discloses an interactive video system having a display for displaying camouflaged information which is discernible only when viewed through a partially transparent viewing screen having zones with light transmission characteristics corresponding to the characteristic of respective displayed image regions. The user of the system is required to input information which can be derived only by recognizing the camouflaged information with the aid of the screen.
Finally, U.S. Pat. No. 4,745,559 discloses a data transmission system in which data templates are downloaded so as to facilitate data transmission and storage. This patent uses a system in which storage templates are locally retrieved and are associated with a unique identifier. The database records are stored locally and are updated from a remote location.
Each of the above systems requires dedicated hardware as shown for example in U.S. Pat. Nos. 5,093,718 and 5,220,420 or the maintenance of a locally stored database. It would be desirable to provide a system in which interactive data could be broadcast to many customer premise equipment devices (CPE). Such devices could obtain control, graphical and audio data by recognizing and accepting specific data files within broadcast data streams and acting upon the data files such that the viewer would achieve the simulation of an interactive television system. The system would broadcast data files which would be selectively retrieved by the individual viewer on a CPE. The files would be broadcast to all CPE'S in the system. The executing program could become resident and active at the CPE by being loaded from a data stream within a broadcast video channel; a data stream within a broadcast data channel; a pointcast data signal directed to a specific CPE or memory storage within the CPE. End user responses could be transmitted back to the provider using the network return data path. In this way, new files could be broadcast through the system such that the system could access the new information.